Our fellow Americans, before we make the case for why the “crisis” over the proposed border wall or “fence” or “steel slats” or security or whatever the issue has morphed into today is a raging caravan of alternative facts, please allow us a moment to appreciate all the long-suffering fact-checkers in the media landscape whose job it was to tally the ways in which President Donald Trump’s Oval Office address was misleading or untruthful or just plain weird. As they say in the American Southwest: Dios los bendiga.

We feel a kinship with these hardy souls because we watched first-hand as The Sun’s own newsroom scrambled into action within minutes after President Trump said this: “In Maryland, MS-13 gang members who arrived in the United States as unaccompanied minors were arrested and charged last year after viciously stabbing and beating a 16-year-old girl.” That sounds terrible. Turns out, it’s also not true. Oh, there has been MS-13 activity in the state, even killings, just not the one described in Tuesday’s prime time address.

Is anyone surprised? Do the president’s supporters even care? As comedian Stephen Colbert once observed, there is a “truthiness” to the claim, meaning it fulfills one’s intuition even if the facts don’t line up. Sticking to the truth? That’s for lesser creatures like journalists, one supposes. It’s not just Mr. Trump who doesn’t care to be constrained by reality, it’s whoever writes his speeches. And it continued on Wednesday and Thursday as he held, and walked out of, a meeting with Democratic leaders and then flew to South Texas to inspect the border right after telling reporters back in D.C. he never said Mexico would directly pay for the wall when, in fact, he did — as The Washington Post has helpfully chronicled.

So really, the mystery stabbing in Maryland is just part and parcel of the overall messaging — familiar as it was — that the nation’s southern border is facing an immediate crisis that only spending $5.6 billion on a wall or fence or slats or whatever can resolve. We’ve been hearing variations on these themes since the 2016 campaign. It isn’t convincing and frankly, it’s even less convincing when Mr. Trump reads it from a teleprompter behind his desk then when he shouts it to an audience of rabid supporters at one of his patented MAGA rallies. At least the strong emotions expressed at a rally can cloud reasoning. What’s the excuse now?

Should we list all the misleading claims? The wall is unlikely to be paid for by a trade deal with Mexico that hasn’t even been approved by Congress. The claims of illegal activity are vastly overstated and take place far from the border. (Here’s one example from 2018: ICE claims 1,641 homicide convictions but reports only 387 charges filed.) Drugs aren’t coming across open land borders but through checkpoints and ports of entry unaffected by a new wall. The physical barrier Democrats have supported in the past (non-contiguous fencing) was different form what the president is pitching now. And “thousands” of immigrants aren’t attempting to enter the country every day.

That last one deserves a little emphasis. The U.S. isn’t facing a border crisis because illegal border crossings are far below where they once were. In 2000, federal agents apprehended more than 1.6 million people at the border. Now, it’s less than one-quarter that number. And as for humanitarian concerns? Perhaps the president should look in the mirror: His own policy choices from separating children from their parents to cracking down on forms of legal immigration have contributed greatly to the inhumane circumstances.

We’ll say this much in defense of the president: The Democrats’ rebuttal — with its stony visages of Senate Minority Leader Chuck Schumer and House Speaker Nancy Pelosi — wasn’t especially compelling either. But at least the facts are on their side, and so is public opinion. Whatever it takes to end the current standoff can’t happen soon enough — even if it means a disastrous attempt to use emergency powers. Shutting down so much of the federal government including (oh, the irony), withholding pay for the U.S. Coast Guard, which confiscates far more heroin than any border control agent ever laid eyes on, was a foolish hostage-taking. Now, Mr. Trump needs to find a way to declare victory, or loss — or maybe just write another fundraising letter — and stop this nonsense ASAP.

Mr. Trump didn’t make the case for a crisis at the southern border this week, not for lack of trying or willingness to misrepresent, but because he’s run out of arguments that haven’t already been knocked down. At least he didn’t claim it’s about stopping terrorists again. Even the president seems to recognize that some dead horses are too absurd — or “alternative” — to keep flogging.